JP7103350B2 - Coreless substrate prepreg, coreless substrate, coreless substrate manufacturing method and semiconductor package - Google Patents

Description

The present invention relates to a prepreg for a coreless substrate, a coreless substrate using the prepreg, a method for manufacturing a coreless substrate, and a semiconductor package.

Due to the recent miniaturization and higher performance of electronic devices, printed wiring boards are required to have higher wiring densities and higher integrations as well as thinner substrates than before.
As a package structure based on these requirements, for example, Patent Document 1 and Patent Document 2 propose a coreless substrate mainly composed of a build-up layer capable of high-density wiring without having a core substrate. .. This coreless substrate is obtained by forming a build-up layer on a support (core substrate) such as a metal plate and then removing the support (core substrate), that is, in this case, the build-up layer. Only. As the build-up layer used for forming the coreless substrate, a prepreg obtained by impregnating a glass cloth with a resin composition, an insulating resin containing no glass cloth, or the like is used.

Since the rigidity of the coreless substrate is reduced by thinning the coreless substrate by removing the support (core substrate), the problem that the semiconductor package warps when the semiconductor element is mounted and packaged becomes more remarkable. Warpage is considered to be one of the factors that cause poor connection between a semiconductor element and a printed wiring board, and a more effective reduction in warpage is desired in a coreless substrate.

One of the factors that cause the semiconductor package to warp is the difference in the coefficient of thermal expansion between the semiconductor element and the printed wiring board. In general, since the coefficient of thermal expansion of a printed wiring board is larger than the coefficient of thermal expansion of a semiconductor element, stress is generated due to the thermal history applied when the semiconductor element is mounted, and warpage occurs. Therefore, in order to suppress the warpage of the semiconductor package, it is necessary to reduce the coefficient of thermal expansion of the printed wiring board to reduce the difference from the coefficient of thermal expansion of the semiconductor element, which is the same even for a coreless substrate. Is. Therefore, the build-up layer used for the coreless substrate is required to have a low coefficient of thermal expansion.
Patent Document 3 discloses a method of laminating an insulating resin containing no glass cloth on both sides of a prepreg as an insulating layer, but in this method, the coefficient of thermal expansion is large, so that the warp tends to be large. ..

Here, it is generally known that the coefficient of thermal expansion of the prepreg obtained by impregnating the glass cloth with the resin composition follows the Scapery formula represented by the following formula.
A ≒ (ArErFr + AgEgFg) / (ErFr + EgFg)
(In the above formula, A is the coefficient of thermal expansion of the prepreg, Ar is the coefficient of thermal expansion of the resin composition, Er is the coefficient of elasticity of the resin composition, Fr is the volume fraction of the resin composition, and Ag is the coefficient of thermal expansion of the glass cloth. , Eg represents the coefficient of elasticity of the glass cloth, and Fg represents the volume fraction of the glass cloth.)
From the above Scapery equation, it can be seen that when glass cloth having the same physical characteristics at an arbitrary volume fraction is used, the prepreg can be reduced in thermal expansion by reducing the elastic modulus and the coefficient of thermal expansion of the resin composition.

For example, Patent Document 4 discloses a prepreg formed of a resin composition containing a specific low elasticity component and a woven fabric base material as a prepreg capable of reducing warpage of a semiconductor package.

Japanese Unexamined Patent Publication No. 2005-72085 JP-A-2002-26171 Japanese Unexamined Patent Publication No. 2009-231222 Japanese Unexamined Patent Publication No. 2015-189834

However, as shown in Patent Document 4, the prepreg having a reduced elastic modulus of the resin composition is greatly affected by the load applied to the build-up layer due to the decrease in rigidity. For example, via holes are formed by a laser or the like after the build-up layer is formed. In the process, the metal circuit may peel off. Therefore, it is required to improve the adhesive strength with the metal circuit.

In view of these circumstances, an object of the present invention is to use a prepreg for a coreless substrate that can satisfy the levels of low thermal expansion, adhesive strength with a metal circuit, heat resistance and desmear resistance required for a coreless substrate, and a prepreg for the coreless substrate. It is to provide a coreless substrate, a method for manufacturing a coreless substrate, and a semiconductor package.

As a result of intensive studies to achieve the above object, the present inventors have found a prepreg containing a thermosetting resin composition containing a (meth) acrylic elastomer and a specific thermosetting resin. We have arrived at the present invention by finding that it is in line with the object.

That is, the present invention provides the following [1] to [9].
[1] Heat containing a (meth) acrylic elastomer (a), an amine compound (b) having at least two primary amino groups, and a maleimide compound (c) having at least two N-substituted maleimide groups. A prepreg for a coreless substrate, which comprises a curable resin composition.
[2] The content of the (meth) acrylic elastomer (a) is 1 to 60 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition, according to the above [1]. Prepreg for coreless boards.
[3] The above [1] or [2], wherein the (meth) acrylic elastomer (a) has one or more reactive functional groups selected from the group consisting of an epoxy group, a hydroxyl group, a carboxy group, an amino group and an amide group. ] The prepreg for the coreless substrate described in.
[4] The prepreg for a coreless substrate according to any one of [1] to [3] above, wherein the thermosetting resin composition further contains a thermosetting resin (d).
[5] The prepreg for a coreless substrate according to any one of the above [1] to [4], wherein the thermosetting resin composition further contains a curing accelerator (e).
[6] The prepreg for a coreless substrate according to any one of [1] to [5] above, wherein the thermosetting resin composition further contains an inorganic filler (f).
[7] A coreless substrate containing an insulating layer formed by using the prepreg for a coreless substrate according to any one of the above [1] to [6].
[8] A semiconductor package in which a semiconductor element is mounted on the coreless substrate according to the above [7].
[9] A method for manufacturing a coreless substrate in which a build-up layer is formed on a support and then the build-up layer is separated from the support.
The build-up consists of alternating layers of insulation and conductors.
A method for manufacturing a coreless substrate, wherein at least one layer of the insulating layer is formed by using the prepreg for a coreless substrate according to any one of the above [1] to [6].

According to the present invention, a prepreg for a coreless substrate that can satisfy the levels of low thermal expansion, adhesive strength with a metal circuit, heat resistance and desmear resistance required for a coreless substrate, and a coreless substrate and coreless using the prepreg. A method for manufacturing a substrate and a semiconductor package can be provided.

It is a schematic diagram which shows one aspect of the manufacturing method of the coreless substrate of this invention.

In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. Further, the lower limit value and the upper limit value of the numerical range are arbitrarily combined with the lower limit value and the upper limit value of the other numerical range, respectively.
Further, as for each component and material exemplified in this specification, one kind may be used alone or two or more kinds may be used in combination unless otherwise specified. In the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.
The present invention also includes aspects in which the items described in the present specification are arbitrarily combined.

[Prepreg for coreless board]
The coreless substrate prepreg of the present invention (hereinafter, also simply referred to as “prepreg”) contains a (meth) acrylic elastomer (a) (hereinafter, also referred to as “component (a)”) and at least two primary amino groups. Amine compound (b) having (hereinafter, also simply referred to as "amine compound (b)" or "component (b)"), and a maleimide compound (c) having at least two N-substituted maleimide groups (hereinafter, simply "" A prepreg for a coreless substrate, which comprises a thermosetting resin composition containing a maleimide compound (c) or a component (c).
The prepreg of the present invention maintains excellent heat resistance and desmear resistance, has excellent low thermal expansion property, and has excellent adhesive strength with a metal circuit. Therefore, it has excellent heat resistance like an insulating layer of a coreless substrate. It has adhesive strength with a metal circuit, and is particularly suitable for applications where improvement in warpage due to thinning is required.
Hereinafter, each component contained in the thermosetting resin composition used for producing the prepreg of the present invention will be described in order.

<(Meta) Acrylic Elastomer (a)>
By containing the thermosetting resin composition containing the (meth) acrylic elastomer (a), the prepreg of the present invention can reduce the elastic modulus while maintaining good adhesive strength with the metal circuit. The reason is not clear, but the flexible acrylic skeleton of the component (a) and the maleimide skeleton of the component (c), which has a strong adhesive force, form a sea-island structure in an appropriate form and exhibit their respective characteristics without bias. It is thought that it can be done.

The (meth) acrylic elastomer (a) is a polymer containing at least a structural unit derived from the (meth) acrylic acid ester. The structural unit derived from the (meth) acrylic acid ester means a structural unit formed when the vinyl bond of the (meth) acrylic acid ester is addition-polymerized. In addition, in this specification, "(meth) acrylic acid" means one or more kinds selected from the group consisting of acrylic acid and methacrylic acid.
The (meth) acrylic elastomer (a) may be used alone or in combination of two or more.

Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic. Isobutyl acid, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, (meth) Examples thereof include, but are not limited to, lauryl acrylate and benzyl (meth) acrylate.
The (meth) acrylic elastomer (a) may contain a structural unit derived from two or more kinds of (meth) acrylic acid esters, and is composed of a structural unit derived from two or more kinds of (meth) acrylic acid esters. It may be a thing.

The (meth) acrylic elastomer (a) may contain a structural unit derived from a monomer other than the (meth) acrylic acid ester.
Examples of the monomer other than the (meth) acrylic acid ester include vinyl-based monomers such as acrylonitrile, (meth) acrylamide, (meth) acrylic acid, styrene, ethylene, propylene, and butadiene. The (meth) acrylic elastomer (a) may contain a structural unit derived from a monomer other than two or more kinds of (meth) acrylic acid esters.

The (meth) acrylic elastomer (a) may further have a reactive functional group at at least one of the molecular terminal and the molecular chain. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxy group, an amino group, an amide group, an isocyanato group, a (meth) acrylic group, a vinyl group and the like. By having these reactive functional groups, the compatibility with other resin components is improved, and the internal stress generated at the time of curing of the thermosetting resin composition can be more effectively reduced, and as a result, it is possible to reduce the internal stress generated at the time of curing. It is possible to remarkably reduce the warp of the substrate. In particular, from the viewpoint of low thermal expansion and adhesive strength with a metal circuit, it is preferable to have at least one selected from the group consisting of an epoxy group, a hydroxyl group, a carboxy group, an amino group and an amide group, and has heat resistance and insulation reliability. From the viewpoint of properties, it is more preferable to have one or more selected from the group consisting of an epoxy group, a hydroxyl group and an amide group.
When an epoxy group is used as the reactive functional group, the functional group equivalent is preferably 0.01 to 0.5 eq / kg, more preferably 0.03 to 0.4 eq / kg, and 0.05 to 0.3 eq / kg. kg is more preferred.
When it has a hydroxyl group as a reactive functional group, its hydroxyl value is preferably 5 to 100 mgKOH / g, more preferably 10 to 50 mgKOH / g, and even more preferably 15 to 30 mgKOH / g.

The weight average molecular weight (Mw) of the (meth) acrylic elastomer (a) is not particularly limited, but is preferably 1,000 to 2,000,000, more preferably 10,000 to 1,500,000, and 100,000. It is more preferably from 1400,000, and particularly preferably from 300,000 to 1,300,000. When the weight average molecular weight (Mw) is at least the lower limit value, the lower elastic modulus tends to be more excellent, and when it is at least the upper limit value, the compatibility and fluidity tend to be more excellent. The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) and converted by a calibration curve prepared using standard polystyrene.

The content of the (meth) acrylic elastomer (a) is excellent in compatibility with other resin components, and from the viewpoint of effectively reducing the elastic modulus of the cured product, the solid resin component in the thermosetting resin composition is solid. With respect to 100 parts by mass, 1 to 60 parts by mass is preferable, 5 to 50 parts by mass is more preferable, and 10 to 30 parts by mass is further preferable. When the content of the (meth) acrylic elastomer (a) is within the above range, a sea-island structure can be appropriately formed in the cured product, and the elasticity due to the flexible (meth) acrylic elastomer (a). It is possible to achieve a high degree of compatibility between the reduction of the rate and the adhesive strength of the maleimide compound (c) with the excellent metal circuit.
Here, the solid content in the present embodiment means a component in the composition other than a volatile substance such as water and a solvent described later. That is, the solid content includes liquid, starch syrup-like or wax-like substances at room temperature around 25 ° C., and does not necessarily mean that it is solid.

<Amine compound (b) having at least two primary amino groups>
The amine compound (b) is not particularly limited as long as it is an amine compound having at least two primary amino groups.
The amine compound (b) is preferably an amine compound having two primary amino groups, and more preferably a diamine compound represented by the following general formula (b-1).

（一般式（ｂ－１）中、Ｘ^ｂ１は、下記一般式（ｂ１－１）、（ｂ１－２）又は（ｂ１－３）で表される基である。）

(In the general formula (b-1), X ^b1 is a group represented by the following general formula (b1-1), (b1-2) or (b1-3).)

（一般式（ｂ１－１）中、Ｒ^ｂ１は各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子である。ｐは０～４の整数である。）

(In the general formula (b1-1), R ^b1 is an aliphatic hydrocarbon group or a halogen atom having 1 to 5 carbon atoms independently. P is an integer of 0 to 4.)

（一般式（ｂ１－２）中、Ｒ^ｂ２及びＲ^ｂ３は各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子である。Ｘ^ｂ２は炭素数１～５のアルキレン基、炭素数２～５のアルキリデン基、エーテル基、スルフィド基、スルホニル基、カルボニルオキシ基、ケト基、単結合又は下記一般式（ｂ１－２－１）で表される基である。ｑ及びｒは各々独立に０～４の整数である。）

（一般式（ｂ１－２－１）中、Ｒ^ｂ４及びＲ^ｂ５は各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子である。Ｘ^ｂ３は炭素数１～５のアルキレン基、炭素数２～５のアルキリデン基、エーテル基、スルフィド基、スルホニル基、カルボニルオキシ基、ケト基又は単結合である。ｓ及びｔは各々独立に０～４の整数である。）

(In the general formula (b1-2), R ^b2 and R ^b3 are independently aliphatic hydrocarbon groups or halogen atoms having 1 to 5 carbon atoms. X ^b2 is an alkylene group having 1 to 5 carbon atoms and carbon. The numbers 2 to 5 are an alkylidene group, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, a single bond, or a group represented by the following general formula (b1-2-1). Q and r are each. It is an independently integer from 0 to 4.)

(In the general formula (b1-2-1), R ^b4 and R ^b5 are independently aliphatic hydrocarbon groups or halogen atoms having 1 to 5 carbon atoms. X ^b3 is an alkylene group having 1 to 5 carbon atoms. , Alkylidene group, ether group, sulfide group, sulfonyl group, carbonyloxy group, keto group or single bond having 2 to 5 carbon atoms. S and t are independently integers of 0 to 4).

（一般式（ｂ１－３）中、Ｒ^ｂ６、Ｒ^ｂ７、Ｒ^ｂ８及びＲ^ｂ９は各々独立に、炭素数１～５のアルキル基、フェニル基又は置換フェニル基を表す。Ｘ^ｂ４及びＸ^ｂ５は各々独立に、２価の有機基を表し、ｕは２～１００の整数である。）

(In the general formula (b1-3), R ^b6 , R ^b7 , R ^b8 and R ^b9 each independently represent an alkyl group having 1 to 5 carbon atoms, a phenyl group or a substituted phenyl group. X ^b4 and X ^b5 are each. Each independently represents a divalent organic group, where u is an integer from 2 to 100.)

In the general formula (b1-1), examples of the aliphatic hydrocarbon group represented by R ^b1 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a t-butyl group. , N-pentyl group and the like. The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and more preferably a methyl group. Further, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
Among the above, an aliphatic hydrocarbon group having 1 to 5 carbon atoms is preferable as R ^b1 .
p is an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 2 from the viewpoint of availability. When p is an integer of 2 or more, the plurality of R ^b1s may be the same or different.

In the general formula (b1-2), examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ^b2 and R ^b3 and the halogen atom are the same as those in the case of R ^b1 . The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, more preferably a methyl group and an ethyl group, and further preferably an ethyl group.
Examples of the alkylene group having 1 to 5 carbon atoms represented by X ^b2 include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group and the like. Can be mentioned. The alkylene group is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group, from the viewpoint of heat resistance and low thermal expansion.
Examples of the alkylidene group having 2 to 5 carbon atoms represented by X ^b2 include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group and an isopentylidene group. Among these, an isopropylidene group is preferable from the viewpoint of heat resistance and low thermal expansion.
Among the above options, X ^b2 is preferably an alkylene group having 1 to 5 carbon atoms and an alkylidene group having 2 to 5 carbon atoms. More preferred are as described above.
q and r are each independently an integer of 0 to 4, and from the viewpoint of availability, both are preferably an integer of 0 to 2, more preferably 0 or 2. When q or r is an integer of 2 or more, the plurality of R ^b2s or R ^b3s may be the same or different from each other.

（一般式（ｂ１－２－１’）中のＸ^ｂ３、Ｒ^ｂ４、Ｒ^ｂ５、ｓ及びｔは、一般式（ｂ１－２－１）中のものと同じであり、好ましいものも同じである。）In the general formula (b1-2-1), examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ^b4 and R ^b5 and the halogen atom are the same as those in the cases of R ^b2 and R ^b3 . , The preferred ones are the same.
The alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by X ^b3 are the same as the alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by X ^b2 . The same is true for the preferred ones.
Among the above options, X ^b3 is preferably an alkylidene group having 2 to 5 carbon atoms, and more preferable one is as described above.
s and t are integers of 0 to 4, and from the viewpoint of availability, both are preferably integers of 0 to 2, more preferably 0 or 1, and even more preferably 0. When s or t is an integer of 2 or more, the plurality of R ^b4s or R ^b5s may be the same or different from each other.
The general formula (b1-2-1) is preferably represented by the following general formula (b1-2-1').

(X ^b3 , R ^b4 , R ^b5 , s and t in the general formula (b1-2-1') are the same as those in the general formula (b1-2-1), and the preferable ones are also the same. .)

（一般式（ｂ１－２’）中のＸ^ｂ２、Ｒ^ｂ２、Ｒ^ｂ３、ｑ及びｒは、一般式（ｂ１－２）中のものと同じであり、好ましいものも同じである。）The group represented by the general formula (b1-2) is preferably a group represented by the following general formula (b1-2'), and any of the following formulas (b1-i) to (b1-iii). It is more preferable that the group is represented by the following formula (b1-ii) or (b1-iii).

(X ^b2 , R ^b2 , R ^b3 , q and r in the general formula (b1-2') are the same as those in the general formula (b1-2'), and the preferable ones are also the same.)

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^b6 , R ^b7 , R ^b8 and R ^b9 in the general formula (b1-3) include a methyl group, an ethyl group, an n-propyl group and an isopropyl group. Examples thereof include an n-butyl group, an isobutyl group, a t-butyl group and an n-pentyl group. As the alkyl group, an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is more preferable.
Examples of the substituent contained in the phenyl group in the substituted phenyl group include an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and an alkynyl group having 2 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include the same alkyl groups as those described above. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group and an allyl group. Examples of the alkynyl group having 2 to 5 carbon atoms include an ethynyl group and a propargyl group.
R ^b6 , R ^b7 , R ^b8 and R ^b9 are all preferably alkyl groups having 1 to 5 carbon atoms, and more preferably methyl groups.
Examples of the divalent organic group represented by X ^b4 and X ^b5 include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, —O— or a divalent linking group in which these are combined. Examples of the alkylene group include an alkylene group having 1 to 10 carbon atoms such as a methylene group, an ethylene group and a propylene group. Examples of the alkenylene group include an alkenylene group having 2 to 10 carbon atoms. Examples of the alkynylene group include an alkynylene group having 2 to 10 carbon atoms. Examples of the arylene group include an arylene group having 6 to 20 carbon atoms such as a phenylene group and a naphthylene group.

In the general formula (b-1), X ^b1 may be any of the groups represented by the general formula (b1-1), (b1-2) or (b1-3), and these Above all, the group represented by the general formula (b1-3) is preferable from the viewpoint of low thermal expansion property and adhesive strength with the metal circuit.

Specific examples of the component (b) include diaminobenzidine, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenylsulfone, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-. Diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl-6,6'-disulfonic acid, 2,2', 5,5' -Tetrachloro-4,4'-diaminobiphenyl, 4,4'-methylene-bis (2-chloroaniline), 1,3'-bis (4-aminophenoxy) benzene, 2,2'-bis [4- (4-Aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4'-bis (4-aminophenoxy) Biphenyl, 2,2'-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4'-bis (4-aminophenoxy) benzene, 4,4'-diaminodiphenyl sulfide, 2,2' -Dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-biphenyldiol, 9,9'-bis (4-aminophenyl) fluorene, o-trizine sulfone, first at the end of the molecule Examples thereof include modified siloxane compounds having a secondary amino group. Among these, a modified siloxane compound having a primary amino group at the molecular terminal is preferable from the viewpoint of heat resistance, desmear resistance, low thermal expansion property, and adhesive strength with a metal circuit.

As the modified siloxane compound having a primary amino group at the end of the molecule, a modified siloxane compound having a primary amino group at both ends of the molecule (hereinafter, also referred to as “both-terminal diamine-modified siloxane”) is preferable, and the above general formula ( As X ^b1 in b-1), a compound having a group represented by the general formula (b1-3) is more preferable.
As the both-terminal diamine-modified siloxane, a commercially available product can be used. For example, a modified siloxane compound "PAM-E" having a primary amino group at both ends (functional group equivalent of amino group 130 g / mol), "KF". -8010 "(functional group equivalent of amino group 430 g / mol)," X-22-161A "(functional group equivalent of amino group 800 g / mol)," X-22-161B "(functional group equivalent of amino group 1, 500 g / mol), "KF-8012" (functional group equivalent of amino group 2,200 g / mol), "KF-8008" (functional group equivalent of amino group 5,700 g / mol) [above, Shinetsu Chemical Industry Co., Ltd. ], "BY16-871" (functional group equivalent of amino group 130 g / mol), "BY16-853U" (functional group equivalent of amino group 460 g / mol) [above, manufactured by Toray Dow Corning Co., Ltd.] and the like. Be done. Among these, "X-22-161A" and "X-22-161B" are preferable from the viewpoint of high reactivity and lower thermal expansion.

The functional group equivalent of the amino group of the modified siloxane compound having a primary amino group at the molecular terminal is not particularly limited, but is preferably 300 to 3,000 g / mol, more preferably 400 to 2,500 g / mol, and 600 to 600 to mol. 2,000 g / mol is more preferable.

The content of the component (b) is preferably 3 to 50 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition from the viewpoint of low thermal expansion and adhesive strength with the metal circuit. 5 to 30 parts by mass is more preferable, and 7 to 20 parts by mass is further preferable.

<Maleimide compound (c) having at least two N-substituted maleimide groups>
The maleimide compound (c) is not particularly limited as long as it is a maleimide compound having at least two N-substituted maleimide groups.
As the maleimide compound (c), a maleimide compound having two N-substituted maleimide groups is preferable, and a compound represented by the following general formula (c-1) is more preferable.

（一般式（ｃ－１）中、Ｘ^ｃ１は、下記一般式（ｃ１－１）、（ｃ１－２）、（ｃ１－３）又は（ｃ１－４）で表される基である。）

(In the general formula (c-1), X ^c1 is a group represented by the following general formulas (c1-1), (c1-2), (c1-3) or (c1-4)).

（一般式（ｃ１－１）中、Ｒ^ｃ１は各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子である。ｐ１は０～４の整数である。）

(In the general formula (c1-1), R ^c1 is an aliphatic hydrocarbon group or a halogen atom having 1 to 5 carbon atoms, respectively. P1 is an integer of 0 to 4.)

（一般式（ｃ１－２）中、Ｒ^ｃ２及びＲ^ｃ３は各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子である。Ｘ^ｃ２は炭素数１～５のアルキレン基、炭素数２～５のアルキリデン基、エーテル基、スルフィド基、スルホニル基、カルボニルオキシ基、ケト基、単結合又は下記一般式（ｃ１－２－１）で表される基である。ｑ１及びｒ１は各々独立に０～４の整数である。）

(In the general formula (c1-2), R ^c2 and R ^c3 are independently aliphatic hydrocarbon groups or halogen atoms having 1 to 5 carbon atoms. X ^c2 is an alkylene group having 1 to 5 carbon atoms and carbon. The numbers 2 to 5 are an alkylidene group, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, a single bond, or a group represented by the following general formula (c1-2-1). Q1 and r1 are each. It is an independently integer from 0 to 4.)

（一般式（ｃ１－２－１）中、Ｒ^ｃ４及びＲ^ｃ５は各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子である。Ｘ^ｃ３は炭素数１～５のアルキレン基、炭素数２～５のアルキリデン基、エーテル基、スルフィド基、スルホニル基、カルボニルオキシ基、ケト基又は単結合である。ｓ１及びｔ１は各々独立に０～４の整数である。）

(In the general formula (c1-2-1), R ^c4 and R ^c5 are independently aliphatic hydrocarbon groups or halogen atoms having 1 to 5 carbon atoms. X ^c3 is an alkylene group having 1 to 5 carbon atoms. , Alkylidene group, ether group, sulfide group, sulfonyl group, carbonyloxy group, keto group or single bond having 2 to 5 carbon atoms. S1 and t1 are independently integers of 0 to 4).

（一般式（ｃ１－３）中、ｎ１は１～１０の整数である。）

(In the general formula (c1-3), n1 is an integer of 1 to 10.)

（一般式（ｃ１－４）中、Ｒ^ｃ６及びＲ^ｃ７は各々独立に、水素原子又は炭素数１～５の脂肪族炭化水素基である。ｕ１は１～８の整数である。）

(In the general formula (c1-4), R ^c6 and R ^c7 are independently hydrogen atoms or aliphatic hydrocarbon groups having 1 to 5 carbon atoms. U1 is an integer of 1 to 8).

In the general formula (c1-1), examples of the aliphatic hydrocarbon group represented by R ^c1 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a t-butyl group. , N-pentyl group and the like. The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and more preferably a methyl group. Further, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
Among the above, an aliphatic hydrocarbon group having 1 to 5 carbon atoms is preferable as R ^c1 .
p1 is an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0, from the viewpoint of availability. When p1 is an integer of 2 or more, the plurality of R ^c1s may be the same or different.

In the general formula (c1-2), examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ^c2 and R ^c3 and the halogen atom are the same as those in the case of R ^c1 . The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, more preferably a methyl group and an ethyl group, and further preferably an ethyl group.
Examples of the alkylene group having 1 to 5 carbon atoms represented by X ^c2 include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group and the like. Can be mentioned. The alkylene group is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group, from the viewpoint of heat resistance and low thermal expansion.
Examples of the alkylidene group having 2 to 5 carbon atoms represented by X ^c2 include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group and an isopentylidene group. Among these, an isopropylidene group is preferable from the viewpoint of heat resistance and low thermal expansion.
Among the above options, X ^c2 is preferably an alkylene group having 1 to 5 carbon atoms and an alkylidene group having 2 to 5 carbon atoms. More preferred are as described above.
q1 and r1 are each independently an integer of 0 to 4, and from the viewpoint of availability, both are preferably an integer of 0 to 2, more preferably 0 or 2. When q1 or r1 is an integer of 2 or more, the plurality of R ^c2s or R ^c3s may be the same or different from each other.

In the general formula (c1-2-1), examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ^c4 and R ^c5 and the halogen atom are the same as those in the cases of R ^c2 and R ^c3 . , The preferred ones are the same.
The alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by X ^c3 are the same as the alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by X ^c2 . The same is true for the preferred ones.
Among the above options, X ^c3 is preferably an alkylidene group having 2 to 5 carbon atoms, and more preferable one is as described above.
s1 and t1 are integers of 0 to 4, and from the viewpoint of availability, both are preferably integers of 0 to 2, more preferably 0 or 1, and even more preferably 0. When s1 or t1 is an integer of 2 or more, the plurality of R ^c4s or R ^c5s may be the same or different from each other.
Further, the general formula (c1-2-1) is preferably represented by the following general formula (c1-2-1').

（一般式（ｃ１－２－１’）中のＸ^ｃ３、Ｒ^ｃ４、Ｒ^ｃ５、ｓ１及びｔ１は、一般式（ｃ１－２－１）中のものと同じであり、好ましいものも同じである。）

(X ^c3 , R ^c4 , R ^c5 , s1 and t1 in the general formula (c1-2-1') are the same as those in the general formula (c1-2-1), and the preferred ones are also the same. .)

The group represented by the general formula (c1-2) is preferably a group represented by the following general formula (c1-2'), and any one of the following (c1-i) to (c1-iii). It is more preferable that the group is represented by (c1-i) or (c1-ii) below.

（一般式（ｃ１－２’）中のＸ^ｃ２、Ｒ^ｃ２、Ｒ^ｃ３、ｑ１及びｒ１は、一般式（ｃ１－２）中のものと同じであり、好ましいものも同じである。）

(X ^c2 , R ^c2 , R ^c3 , q1 and r1 in the general formula (c1-2') are the same as those in the general formula (c1-2'), and the preferable ones are also the same.)

In the general formula (c1-3), n1 is an integer of 1 to 10, preferably an integer of 1 to 5, and more preferably an integer of 1 to 3 from the viewpoint of availability.
In the general formula (c1-4), the aliphatic hydrocarbon groups having 1 to 5 carbon atoms represented by R ^c6 and R ^c7 are the same as those in the case of R ^c1 in the general formula (c1-1). , The preferred ones are the same. u1 is an integer of 1 to 8, preferably an integer of 1 to 3, and more preferably 1.

In the general formula (c-1), X ^c1 is any of the groups represented by the general formula (c1-1), (c1-2), (c1-3) or (c1-4). Of these, the group represented by (c1-2) is preferable from the viewpoint of low thermal expansion and flexural modulus.

Specific examples of the component (c) include bis (4-maleimidephenyl) methane, polyphenylmethane maleimide, bis (4-maleimidephenyl) ether, bis (4-maleimidephenyl) sulfone, 3,3'-dimethyl-5. , 5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, 2,2-bis [4- (4-maleimidephenoxy) phenyl] propane And so on.
Among these, bis (4-maleimidephenyl) methane, bis (4-maleimidephenyl) sulfone, 3,3'-dimethyl-5,5'-diethyl from the viewpoint of high reactivity and higher heat resistance. -4,4'-diphenylmethane bismaleimide, 2,2-bis [4- (4-maleimide phenoxy) phenyl] propane is preferable, and 3,3'-dimethyl-5,5'from the viewpoint of solubility in a solvent. -Diethyl-4,4'-diphenylmethane Bismaleimide and bis (4-maleimidephenyl) methane are more preferable, and bis (4-maleimidephenyl) methane is further preferable from the viewpoint of production cost.

The content of the component (c) is preferably 20 to 90 parts by mass, preferably 30 to 70 parts by mass, based on 100 parts by mass of the solid content of the resin component in the thermosetting resin composition from the viewpoint of elastic modulus and low thermal expansion. Parts by mass are more preferable, and 40 to 60 parts by mass are even more preferable.

The component (b) and the component (c) may be mixed with the component (a) or the like as they are, or the component (b) and the component (c) may be mixed in advance as necessary before being mixed with the component (a). ) Components are heated and reacted to form an amino-modified polyimide resin [hereinafter referred to as amino-modified polyimide resin (X). ] May be formed. That is, the present invention comprises a (meth) acrylate elastomer (a), an amine compound (b) having at least two primary amino groups and a maleimide compound (c) having at least two N-substituted maleimide groups. Also provided is a coreless substrate prepreg comprising a thermosetting resin composition containing an amino-modified polyimide resin (X) which is a reaction product. By reacting the component (b) and the component (c) in advance to obtain the amino-modified polyimide resin (X), the molecular weight can be controlled, and the low curing shrinkage and the low thermal expansion property can be further improved. .. The amino-modified polyimide resin (X) will be described below.

<Amino-modified polyimide resin (X)>
There is no particular limitation on the reaction method between the component (b) and the component (c). The reaction temperature is preferably 70 to 200 ° C., more preferably 80 to 150 ° C., and even more preferably 100 to 130 ° C. from the viewpoint of productivity and sufficient progress of the reaction. The reaction time is not particularly limited, but is preferably 0.5 to 10 hours, more preferably 1 to 6 hours.

The reaction between the component (b) and the component (c) is preferably carried out in an organic solvent. Examples of the organic solvent include alcohol solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; acetate ethyl ester and γ-butyrolactone. Ester-based solvents such as; ether-based solvents such as tetrahydrofuran; aromatic solvents such as toluene, xylene, mesityrene; nitrogen atom-containing solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone; sulfur atom-containing solvents such as dimethylsulfoxide And so on. These may be used alone or in combination of two or more.
Among these, cyclohexanone, propylene glycol monomethyl ether, methyl cellosolve, and γ-butyrolactone are preferable from the viewpoint of solubility, and cyclohexanone and propylene glycol are preferable from the viewpoint of low toxicity and high volatility and difficult to remain as a residual solvent. Monomethyl ether and dimethylacetamide are preferable, and propylene glycol monomethyl ether is more preferable.
The amount of the organic solvent used is not particularly limited, but from the viewpoint of solubility and reaction rate, 25 to 1,000 parts by mass is preferable with respect to 100 parts by mass in total of the component (b) and the component (c), and 50. It is more preferably up to 500 parts by mass, and even more preferably 50 to 200 parts by mass.

After completion of the above reaction, the obtained reaction mixture is directly mixed with other components without further purification of the reaction product to prepare a thermosetting resin composition containing the amino-modified polyimide resin (X). Can be done.

In the reaction, the ratio of the component (b) to the component (c) used is such that the equivalent of the maleimide group of the component (c) is the first grade of the component (b) from the viewpoint of preventing gelation and heat resistance. It is preferable that the equivalent of the amino group is exceeded, that is, the ratio [(c) / (b)] of the equivalent of the maleimide group of the component (c) to the equivalent of the primary amino group of the component (b) is 1. It is preferably more than, more preferably 2 to 35, still more preferably 10 to 35.

When the thermosetting resin composition contains the amino-modified polyimide resin (X), the content thereof is 40 to 95 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition. Preferably, 50 to 80 parts by mass is more preferable, and 60 to 70 parts by mass is further preferable.

<Thermosetting resin (d)>
The thermosetting resin composition may further contain the thermosetting resin (d), and preferably contains the thermosetting resin (d). However, the thermosetting resin (d) does not contain the component (b) and the component (c). As the thermosetting resin (d), one type may be used alone, or two or more types may be used in combination.
Examples of the thermosetting resin (d) include epoxy resin, phenol resin, unsaturated imide resin (however, the component (c) is not included), cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, and amino resin. (However, the component (b) is not included), unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, melamine resin (however, the component (b) is not included) and the like can be mentioned. .. Among these, one or more selected from the group consisting of epoxy resin and cyanate resin is preferable, and epoxy resin is more preferable, from the viewpoint of moldability and electrical insulation, and from the viewpoint of adhesive strength with a metal circuit.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, α-naphthol / cresol novolac type epoxy resin, and bisphenol A novolac. Type epoxy resin, bisphenol F novolac type epoxy resin, stillben type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin , Naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, alicyclic epoxy resin, polycyclic aromatic diglycidyl ether compounds such as polyfunctional phenols and anthracene, phosphorus-containing epoxy resin in which a phosphorus compound is introduced, etc. Can be mentioned. These may be used alone or in combination of two or more. Among these, a biphenyl aralkyl type epoxy resin and an α-naphthol / cresol novolac type epoxy resin are preferable from the viewpoint of heat resistance and flame retardancy.

When the thermosetting resin composition contains the thermosetting resin (d), the content thereof is 1 to 30 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition. Preferably, 5 to 25 parts by mass is more preferable, and 10 to 20 parts by mass is further preferable.

<Curing accelerator (e)>
The thermosetting resin composition may further contain a curing accelerator (e).
Examples of the curing accelerator (e) include organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III); Examples thereof include imidazoles and derivatives thereof; organic phosphorus compounds; secondary amines; tertiary amines; quaternary ammonium salts and the like. These may be used alone or in combination of two or more. Among these, imidazoles and derivatives thereof are preferable from the viewpoint of heat resistance, flame retardancy and adhesive strength with a metal circuit, and organic phosphorus compounds are preferable from the viewpoint of low thermal expansion.
A commercially available product may be used as the curing accelerator (e). Examples of commercially available products include isocyanate mask imidazole (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: G-8009L), triphenylphosphine triphenylborane (manufactured by Hokuko Chemical Industry Co., Ltd., trade name: TPP-S) and the like. ..
When the thermosetting resin composition contains the curing accelerator (e), the content thereof is 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition. Is preferable, 0.3 to 5 parts by mass is more preferable, and 0.5 to 2 parts by mass is further preferable. When the content of the curing accelerator (e) is 0.1 parts by mass or more, heat resistance, flame retardancy and copper foil adhesiveness tend to be excellent, and when it is 10 parts by mass or less, heat resistance and aging It tends to be excellent in stability and press formability.

<Inorganic filler (f)>
The thermosetting resin composition may further contain an inorganic filler (f).
Examples of the inorganic filler (f) include silica, alumina, titanium oxide, mica, beryria, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, and silicate. Aluminum oxide, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay such as calcined clay, talc, aluminum borate, silicon carbide, quartz powder, short glass fiber, fine glass powder, hollow glass, etc. Can be mentioned. As the glass, E glass, T glass, D glass and the like are preferably mentioned. These may be used alone or in combination of two or more.
Among these, silica is preferable from the viewpoint of dielectric properties, heat resistance and low thermal expansion. Examples of silica include precipitated silica manufactured by a wet method and having a high water content, and dry silica manufactured by a dry method and containing almost no bound water, etc. Further, the dry silica further depends on the difference in the manufacturing method. , Crushed silica, fumed silica, fused spherical silica and the like. Among these, fused spherical silica is preferable from the viewpoint of low thermal expansion and fluidity when filled in a resin.

The average particle size of the inorganic filler (f) is preferably 0.1 to 10 μm, more preferably 0.3 to 8 μm, and even more preferably 0.3 to 3 μm. When the average particle size is 0.1 μm or more, the fluidity when the resin is highly filled tends to be kept good, and when it is 10 μm or less, the mixing probability of coarse particles is reduced and defects caused by coarse particles are deteriorated. There is a tendency that the occurrence can be suppressed. Here, the average particle size is the particle size of a point corresponding to a volume of 50% when the cumulative frequency distribution curve by the particle size is obtained with the total volume of the particles as 100%, and the laser diffraction scattering method is used. It can be measured with the particle size distribution measuring device or the like.
The inorganic filler (f) may be surface-treated with a coupling agent. The method of surface treatment with a coupling agent may be a method of surface-treating the inorganic filler (f) before compounding by a dry method or a wet method, and the surface-untreated inorganic filler (f) may be treated with another inorganic filler (f). A so-called inorganic blend treatment method may be used in which a silane coupling agent is added to the composition after blending with the components to obtain a composition.
Examples of the coupling agent include a silane-based coupling agent, a titanate-based coupling agent, a silicone oligomer and the like.

When the thermosetting resin composition contains the inorganic filler (f), the content thereof is preferably 10 to 300 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition. , 50 to 250 parts by mass is more preferable, and 70 to 180 parts by mass is further preferable. When the content of the inorganic filler (f) is within the above range, moldability and low thermal expansion are good.

When the thermosetting resin composition contains the inorganic filler (f), if necessary, it is treated with a disperser such as a three-roll, a bead mill, or a nanomizer to improve the dispersibility of the inorganic filler (f). It is preferable to improve.

<Other ingredients>
The thermosetting resin composition contained in the prepreg of the present invention has other components such as a flame retardant, an ultraviolet absorber, an antioxidant, a photopolymerization initiator, and an increase in fluorescence to the extent that the thermosetting property is not impaired. It may contain a whitening agent, an adhesiveness improver and the like.
Examples of the flame retardant include aromatic phosphate ester compounds, phosphazenic compounds, phosphinic acid esters, metal salts of phosphinic acid compounds, red phosphorus, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Phosphorus-based flame retardants such as and derivatives thereof; nitrogen-based flame retardants such as guanidine sulfamate, melamine sulfate, melamine polyphosphate, melamine cyanurate; halogen-containing flame retardants containing bromine, chlorine, etc.; inorganic substances such as antimony trioxide. Examples include flame retardants.
Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber.
Examples of the antioxidant include a hindered phenol-based antioxidant, a hindered amine-based antioxidant, and the like.
Examples of the photopolymerization initiator include benzophenones, benzyl ketals, thioxanthone-based photopolymerization initiators, and the like.
Examples of the fluorescent whitening agent include a fluorescent whitening agent of a stilbene derivative.
Examples of the adhesiveness improving agent include urea compounds such as ureasilane and the coupling agent.

The thermosetting resin composition may be in the state of a varnish in which each component is dissolved or dispersed in an organic solvent so that it can be easily used in the production of a prepreg or the like.
Examples of the organic solvent include alcohol solvents such as methanol, ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; butyl acetate and propylene. Ester-based solvents such as glycol monomethyl ether acetate; Ether-based solvents such as tetrahydrofuran; Aromatic solvents such as toluene, xylene and mesitylen; Nitrogen atom-containing solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; Examples include a sulfur atom-containing solvent. These organic solvents may be used alone or in combination of two or more.
Among these, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl cellosolve, and propylene glycol monomethyl ether are preferable from the viewpoint of solubility of each component, methyl ethyl ketone is more preferable, and methyl isobutyl ketone, from the viewpoint of low toxicity. Cyclohexanone and propylene glycol monomethyl ether are more preferable.
The solid content concentration of the varnish is preferably 40 to 90% by mass, more preferably 50 to 80% by mass. When the solid content concentration of the varnish is within the above range, good coatability can be maintained, and a prepreg having an appropriate amount of the thermosetting resin composition attached can be obtained.

The flexural modulus of the prepreg of the present invention is preferably 25 GPa or less, more preferably 20 GPa or less, still more preferably 18 GPa or less, from the viewpoint of warpage reduction. The lower limit of the flexural modulus is, for example, 5 GPa or more, and may be 10 GPa or more.
The flexural modulus can be measured by the method shown in the examples.

The prepreg of the present invention can be produced, for example, by impregnating a fiber base material with the thermosetting resin composition and semi-curing (B-stage) by heating or the like.
As the fiber base material, well-known materials used for various laminated boards for electrical insulating materials can be used. Examples of the material include inorganic fibers such as E glass, S glass, low dielectric glass, and Q glass; organic fibers such as low dielectric glass polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. In particular, from the viewpoint of obtaining a base material having excellent dielectric properties, inorganic fibers are preferable, and low-dielectric glass and Q glass are more preferable.
These fiber substrates have shapes such as woven fabrics, non-woven fabrics, robinks, chopped strand mats, and surfaced mats.
The material and shape of the fiber base material are appropriately selected depending on the intended use and performance of the molded product, and if necessary, the fiber base material may be one type of material and one type of shape, or two types. It may be a fiber base material made of the above materials, or may be a fiber base material having two or more types of shapes. As the fiber base material, for example, one having a thickness of about 0.03 to 0.5 mm can be used. From the viewpoints of heat resistance, moisture resistance, processability, etc., these fiber base materials are preferably surface-treated with a silane coupling agent or the like, or mechanically opened.

In the prepreg of the present invention, for example, the amount of solid content of the thermosetting resin composition attached to the fiber substrate is 20 to 90% by mass in terms of the content of the thermosetting resin composition to the prepreg after drying. preferable.
The prepreg of the present invention is, for example, after impregnating a fiber base material with a thermosetting resin composition so that the amount of solid content of the thermosetting resin composition adhered in the prepreg is within the above range, the temperature is 100 to 200 ° C. It can be produced by heating and drying at a temperature for 1 to 30 minutes and semi-curing (B-stage).

By using the prepreg of the present invention, a laminate containing an insulating layer can be obtained. The laminated board can be manufactured by laminating and molding the prepreg of the present invention. Specifically, one or two to 20 prepregs of the present invention are prepared, and if necessary, metal foils such as copper and aluminum are arranged on one side or both sides thereof for laminating and molding. It can be manufactured by. The metal foil is not particularly limited as long as it is used for electrical insulating material.
For the molding conditions when manufacturing the laminated board, for example, the method of the laminated board for electric insulating material and the multi-layer board can be applied, and a multi-stage press, a multi-stage vacuum press, continuous molding, an autoclave molding machine, etc. are used, and the temperature is 100 to 250. It can be molded at ° C., a pressure of 0.2 to 10 MPa, and a heating time of 0.1 to 5 hours. Further, the prepreg of the present invention and the wiring board for the inner layer can be combined and laminated to produce a laminated plate.
Further, a printed wiring board can be manufactured by circuit-processing the metal foil.

[Manufacturing method of coreless substrate and coreless substrate]
The coreless substrate of the present invention contains an insulating layer formed by using the prepreg for the coreless substrate of the present invention.
The coreless substrate of the present invention can be produced, for example, by forming a build-up layer on a support (core substrate) using the prepreg of the present invention and then separating the support. The method for forming the build-up layer is not particularly limited, and a known method can be adopted. For example, the build-up layer can be formed by the following method (see FIG. 1).
First, the prepreg 2 of the present invention is placed on the support (core substrate) 1. The prepreg 2 may be arranged after the adhesive layer is arranged on the support (core substrate) 1. Then, the prepreg 2 is heat-cured to form an insulating layer. Next, after forming the via hole 3 by a drill cutting method, a laser processing method using a YAG laser, a CO ₂ laser, or the like, surface roughening treatment and desmear treatment are performed as necessary. Subsequently, the circuit pattern 4 is formed by a subtractive method, a full additive method, a semi-additive method (SAP: Semi Additive Process), a modified semi-additive method (m-SAP: modified Semi Additive Process), or the like. By repeating the above process, the build-up layer 5 is formed. A coreless substrate can be obtained by separating the formed build-up layer 5 from the support (core substrate) 1. The screw-up layer 5 may be formed on one side of the support (core substrate) 1 or on both sides.
The coreless substrate of the present invention contains one or more insulating layers obtained by curing the prepreg of the present invention, and may include an insulating layer obtained by curing a prepreg, a resin film, or the like other than the prepreg of the present invention. good.
The coreless substrate of the present invention has a small thickness because it does not have a core substrate, and specifically, it usually has a thickness of usually preferably 15 to 200 mm, more preferably 30 to 150 mm, still more preferably 35 to 100 mm. ..

[Semiconductor package]
The semiconductor package of the present invention is formed by mounting a semiconductor element on the coreless substrate of the present invention, and is manufactured by mounting a semiconductor element such as a semiconductor chip or a memory at a predetermined position on the coreless substrate.

Next, the present invention will be described in more detail with reference to the following examples, but these examples do not limit the present invention.
The performance of the copper-clad laminates obtained in the following examples was measured and evaluated by the following methods.

(1) Coefficient of thermal expansion Evaluation of length (X direction) 5 mm x width (Y direction) 5 mm x thickness (Z direction) 0.4 mm by removing the copper foil by immersing the copper-clad laminate in a copper etching solution. A substrate was prepared, and thermomechanical analysis was performed by a compression method using a TMA test apparatus (manufactured by DuPont, trade name: TMA2940). After the evaluation substrate was mounted on the apparatus in the X direction, the measurement was carried out twice in succession under the measurement conditions of a load of 5 g and a heating rate of 10 ° C./min. The average coefficient of thermal expansion from 30 ° C. to 100 ° C. in the second measurement was calculated and used as the value of the coefficient of thermal expansion.

(2) Copper foil adhesive strength (copper foil peel strength)
By immersing the copper-clad laminate in a copper etching solution, an outer copper layer is formed to a width of 3 mm, one end of the copper layer is peeled off at the interface between the outer layer copper layer and the insulating layer, and the copper-clad laminate is grasped with a gripper, and a tensile tester is used. The adhesiveness (peel strength) of the copper foil when peeled off at room temperature was measured at a tensile speed of about 50 mm / min in the vertical direction.

(3) Glass transition temperature (Tg)
By removing the copper foil by immersing the copper-clad laminate in a copper etching solution, an evaluation substrate of length (X direction) 5 mm x width (Y direction) 5 mm x thickness (Z direction) 0.4 mm was produced, and TMA was produced. Thermomechanical analysis was performed by a compression method using a test device (manufactured by DuPont, trade name: TMA2940). After the evaluation substrate was mounted on the apparatus in the X direction, the measurement was carried out twice in succession under the measurement conditions of a load of 5 g and a heating rate of 10 ° C./min. The Tg indicated by the intersection of the tangents of different thermal expansion curves in the second measurement was obtained and used as an index of heat resistance. The higher the Tg, the better the heat resistance.

(4) Flexural modulus A 50 mm × 25 mm evaluation substrate was prepared by immersing a copper-clad laminate in a copper etching solution to remove the copper foil, and a universal testing machine “Tencilon UCT-5T” (manufactured by Orientec Co., Ltd.) The flexural modulus was measured under the conditions of a crosshead speed of 1 mm / min and an interspan distance of 20 mm. The higher the value, the higher the rigidity.

(5) Desmia weight reduction (Desmia resistance)
A 40 mm × 40 mm evaluation substrate from which the copper foil was removed by immersing the copper-clad laminate in a copper etching solution was subjected to desmear treatment by the steps shown in Table A. The chemical solution used was manufactured by Atotech. The amount of weight loss after the desmear treatment was calculated with respect to the dry weight before the desmear treatment, and this was used as an index of the desmear resistance. The smaller the amount of desmear weight reduction, the better the desmear resistance.

Production Example 1: Production of amino-modified polyimide resin (X-1) In a reaction vessel with a volume of 2 liters that can be heated and cooled equipped with a thermometer, a stirrer, and a moisture meter with a reflux cooling tube, both-terminal diamine-modified siloxanes ( Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: X-22-161A, functional group equivalent of amino group: 800 g / mol, component (b) 72 g, and bis (4-maleimidephenyl) methane (KAI Kasei Co., Ltd.) 252 g of (BMI, component (c)) and 270 g of propylene glycol monomethyl ether were added and reacted at 110 ° C. for 3 hours to obtain an amino-modified polyimide resin (X-1) -containing solution.

Production Example 2: Production of amino-modified polyimide resin (X-2) In a reaction vessel with a volume of 2 liters that can be heated and cooled equipped with a thermometer, a stirrer, and a moisture meter with a reflux cooling tube, both-terminal diamine-modified siloxanes ( Manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: X-22-161B, functional group equivalent of amino group: 1,500 g / mol, component (b) 72 g, and bis (4-maleimidephenyl) methane (KAI Kasei) 252 g of BMI (component (c)) and 270 g of propylene glycol monomethyl ether were added and reacted at 110 ° C. for 3 hours to obtain an amino-modified polyimide resin (X-2) -containing solution. ..

Examples 1-12, Comparative Examples 1-6
Each component shown below is mixed at the blending ratio shown in Tables 1 to 3 (the unit of the numerical value in the table is a mass part, and in the case of a solution, it is a solid content equivalent amount), and methyl ethyl ketone is added to the solvent. A uniform varnish having a solid content concentration of 65% by mass was prepared. Next, this varnish was impregnated and coated on an E glass cloth having a thickness of 0.1 mm, and dried by heating at 160 ° C. for 10 minutes to obtain a prepreg for a coreless substrate having a thermosetting resin composition content of 48% by mass. Obtained.
Four coreless substrate prepregs were stacked, 12 μm electrolytic copper foils were arranged one above the other, and pressed at a pressure of 2.5 MPa and a temperature of 240 ° C. for 60 minutes to obtain a copper-clad laminate. Tables 1 to 3 show the evaluation results obtained according to the measurement method for the obtained copper-clad laminate.

[(Meta) Acrylic Elastomer (a)]
SG-P3: Epoxy group-containing acrylic polymer with a weight average molecular weight of 850,000 [manufactured by Nagase ChemteX Corporation, trade name, epoxy value: 0.21 eq / kg (catalog value)]
SG-80H: Epoxy group- and amide group-containing acrylic polymer with a weight average molecular weight of 350,000 [manufactured by Nagase ChemteX Corporation, trade name, epoxy value: 0.07 eq / kg (catalog value)]
SG-600TEA: Acrylic polymer containing hydroxyl groups with a weight average molecular weight of 1.2 million [manufactured by Nagase ChemteX Corporation, trade name, hydroxyl value: 20 mgKOH / g (catalog value)]

[Amine compound (b) having at least two primary amino groups]
X-22-161A: Diamine-modified siloxane at both ends [manufactured by Shin-Etsu Chemical Co., Ltd., trade name, functional group equivalent of amino group: 800 g / mol]
X-22-161B: Diamine-modified siloxane at both ends [manufactured by Shin-Etsu Chemical Co., Ltd., trade name, functional group equivalent of amino group: 1,500 g / mol]

[Maleimide compound (c) having at least two N-substituted maleimide groups]
・ BMI: Bis (4-maleimidephenyl) methane [manufactured by Keiai Kasei Co., Ltd., trade name]

[Amino-modified polyimide resin (X)]
-X-1: Amino-modified polyimide resin (X-1) -containing solution prepared in Production Example 1-X-2: Amino-modified polyimide resin (X-2) -containing solution prepared in Production Example 2.

[Thermosetting resin (d)]
-NC-7000-L: α-naphthol / cresol novolac type epoxy resin [manufactured by Nippon Kayaku Co., Ltd., trade name]
-NC-3000-H: Biphenyl aralkyl type epoxy resin [manufactured by Nippon Kayaku Co., Ltd., trade name]

[Curing accelerator (e)]
-G-8009L: Isocyanate mask imidazole [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name]
-TPP-S: Triphenylphosphine Triphenylborane [manufactured by Hokuko Chemical Industry Co., Ltd., trade name]

[Inorganic filler (f)]
-Spherical fused silica [average particle size: 0.5 μm]

As is clear from Tables 1 and 2, the copper-clad laminates of Examples 1 to 12 obtained from the prepregs of the present invention have a coefficient of thermal expansion, copper foil adhesiveness, glass transition temperature, flexural modulus and flexural modulus. The amount of desmear weight reduction is excellent, and the copper foil adhesiveness is particularly excellent. On the other hand, as is clear from Table 3, the copper-clad laminates of Comparative Examples 1 to 5 in which the (meth) acrylic elastomer (a) is not used and the copper of Comparative Example 6 in which the amine compound (b) is not used. None of the stretched laminates satisfy all the characteristics of thermal expansion coefficient, copper foil adhesiveness, glass transition temperature, flexural modulus and desmear weight reduction amount at the same time, and are particularly inferior in thermal expansion coefficient. Therefore, it can be seen that the prepreg of the present invention provides a laminated plate having excellent low thermal expansion and adhesive strength with a metal circuit while maintaining excellent heat resistance and desmear resistance.

Since the prepreg of the present invention is a prepreg that maintains excellent heat resistance and desmear resistance, has excellent low thermal expansion properties, and has excellent adhesion strength to a metal circuit, it has a high density and a high number of layers. It is suitable for manufacturing a wiring board, and is preferably used for a wiring board of an electronic device used for a computer, an information device terminal, or the like that processes a large amount of data at high speed.

1 Support (core substrate)
2 prepreg (insulation layer)
3 Via hole 4 Circuit pattern 5 Build-up layer 6 Coreless board

Claims (10)

It contains (meth) an acrylic elastomer (a), an amine compound (b) having at least two primary amino groups, and a maleimide compound (c) having at least two N-substituted maleimide groups .
A prepreg for a coreless substrate comprising a thermosetting resin composition having a weight average molecular weight (Mw) of the (meth) acrylic elastomer (a) of 300,000 to 2,000,000 . (Meta) Acrylic elastomer (a) and
An amino-modified polyimide resin (X), which is a reaction product of an amine compound (b) having at least two primary amino groups and a maleimide compound (c) having at least two N-substituted maleimide groups.
Contains,
A prepreg for a coreless substrate comprising a thermosetting resin composition having a weight average molecular weight (Mw) of the (meth) acrylic elastomer (a) of 300,000 to 2,000,000 . The coreless according to claim 1 or 2 , wherein the content of the (meth) acrylic elastomer (a) is 1 to 60 parts by mass with respect to 100 parts by mass of the solid content of the resin component in the thermosetting resin composition. Prepreg for board. Any one of claims 1 to 3, wherein the (meth) acrylic elastomer (a) has one or more reactive functional groups selected from the group consisting of an epoxy group, a hydroxyl group, a carboxy group, an amino group and an amide group. Prepreg for coreless substrates as described in. The prepreg for a coreless substrate according to any one of claims 1 to 4 , wherein the thermosetting resin composition further contains a thermosetting resin (d). The prepreg for a coreless substrate according to any one of claims 1 to 5 , wherein the thermosetting resin composition further contains a curing accelerator (e). The prepreg for a coreless substrate according to any one of claims 1 to 6 , wherein the thermosetting resin composition further contains an inorganic filler (f). A coreless substrate containing an insulating layer formed by using the prepreg for a coreless substrate according to any one of claims 1 to 7 . A semiconductor package in which a semiconductor element is mounted on the coreless substrate according to claim 8 . A method for manufacturing a coreless substrate in which a build-up layer is formed on a support and then the build-up layer is separated from the support.
The build-up layer is formed by alternately laminating insulating layers and conductor layers.
A method for manufacturing a coreless substrate, wherein at least one layer of the insulating layer is formed by using the prepreg for a coreless substrate according to any one of claims 1 to 7 .

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